Question

unit rates: better buy
calculate the unit rate for each item. round to the nearest hundredth place. then, compare the rates to determine the best - value.

item cost unit rate best value:
30 - wash detergent box $8
55 - wash detergent box $12
70 - wash detergent box $15

item cost unit rate best value:
pack of 24 pencils $26
pack of 12 pencils $11.75
pack of 2 pencils $1.50

item cost unit rate best value:
6 - month subscription $90
12 - month subscription $186
24 - month subscription $372

item cost unit rate best value:
6 cookies $7.50
12 cookies $15
24 cookies $28

Explanation:

Step1: Calculate unit - rate for 30 - wash detergent box

The unit rate is cost per wash. So, divide the cost by the number of washes. For the 30 - wash detergent box with a cost of $8, the unit rate is $\frac{8}{30}\approx0.27$ dollars per wash.

Step2: Calculate unit - rate for 55 - wash detergent box

For the 55 - wash detergent box costing $12, the unit rate is $\frac{12}{55}\approx0.22$ dollars per wash.

Step3: Calculate unit - rate for 70 - wash detergent box

For the 70 - wash detergent box costing $15, the unit rate is $\frac{15}{70}\approx0.21$ dollars per wash.

Step4: Determine best - value for detergent boxes

The 70 - wash detergent box has the lowest unit rate, so it is the best value.

Step5: Calculate unit - rate for pack of 24 pencils

For a pack of 24 pencils costing $26, the unit rate is $\frac{26}{24}\approx1.08$ dollars per pencil.

Step6: Calculate unit - rate for pack of 12 pencils

For a pack of 12 pencils costing $11.75$, the unit rate is $\frac{11.75}{12}\approx0.98$ dollars per pencil.

Step7: Calculate unit - rate for pack of 2 pencils

For a pack of 2 pencils costing $1.50$, the unit rate is $\frac{1.50}{2}=0.75$ dollars per pencil.

Step8: Determine best - value for pencils

The pack of 2 pencils has the lowest unit rate, so it is the best value.

Step9: Calculate unit - rate for 6 - month subscription

For a 6 - month subscription costing $90$, the unit rate is $\frac{90}{6}=15$ dollars per month.

Step10: Calculate unit - rate for 12 - month subscription

For a 12 - month subscription costing $186$, the unit rate is $\frac{186}{12}=15.5$ dollars per month.

Step11: Calculate unit - rate for 24 - month subscription

For a 24 - month subscription costing $372$, the unit rate is $\frac{372}{24}=15.5$ dollars per month.

Step12: Determine best - value for subscriptions

The 6 - month subscription has the lowest unit rate, so it is the best value.

Step13: Calculate unit - rate for 6 cookies

For 6 cookies costing $7.50$, the unit rate is $\frac{7.50}{6}=1.25$ dollars per cookie.

Step14: Calculate unit - rate for 12 cookies

For 12 cookies costing $15$, the unit rate is $\frac{15}{12}=1.25$ dollars per cookie.

Step15: Calculate unit - rate for 24 cookies

For 24 cookies costing $28$, the unit rate is $\frac{28}{24}\approx1.17$ dollars per cookie.

Step16: Determine best - value for cookies

The 24 - cookie pack has the lowest unit rate, so it is the best value.

Answer:

Item	Cost	Unit Rate	Best value
55 - wash detergent box	$12	$0.22 per wash	70 - wash detergent box
70 - wash detergent box	$15	$0.21 per wash	70 - wash detergent box
Pack of 24 pencils	$26	$1.08 per pencil	Pack of 2 pencils
Pack of 12 pencils	$11.75	$0.98 per pencil	Pack of 2 pencils
Pack of 2 pencils	$1.50	$0.75 per pencil	Pack of 2 pencils
6 - month subscription	$90	$15 per month	6 - month subscription
12 - month subscription	$186	$15.5 per month	6 - month subscription
24 - month subscription	$372	$15.5 per month	6 - month subscription
6 cookies	$7.50	$1.25 per cookie	24 - cookies
12 cookies	$15	$1.25 per cookie	24 - cookies
24 cookies	$28	$1.17 per cookie	24 - cookies